1. Field of the Invention
The invention relates to an information display device, and more particularly to an illuminated information display device incorporating a remotely activated switch that cuts off the primary power source and allows the potency of the backup power supply to be verified.
2. Background
Illuminated information display devices are common in our modern society. They typically are found in buildings and take the form of entrance and exit signs and also signs that inform people of various hazards. Most of these devices are colored light emitting display devices, and employ incandescent lamps as the light source and a colored filter for coloring the display's light. For example, an exit display sign uses an incandescent lamp as the light source. This light source is placed inside a housing which has at least one surface relieved to display the indicia of the word "EXIT." A colored filter is commonly placed between the light source and the relieved area so that the word "EXIT" is displayed in color. The light source is arranged within the housing so that the displayed word is uniformly illuminated.
Information display devices are commonly integrated with the structure of a building. This requires a skilled carpenter and an electrician to mount the device. The "hard-mounting" results in additional cost above the initial expense of purchasing the display device. Additionally, many states have enacted building code requirements that require illuminated information devices, such as exit signs, to be placed both at the floor level and the ceiling level of commercial buildings. Most existing buildings, however, have illuminated signs only at ceiling level. The new building code requirements means costly projects to retrofit existing buildings with floor level signs to comply with the code requirements using the current technology.
Many information display devices, like the entrance or the exit signs, are required to operate day and night for safety and security purposes. This means that the light source must stay illuminated at all times, even during power outages. For this reason, such signs typically include a battery back-up. In many cases, such a back-up power source is mandated by building regulations.
In order to insure that the backup power supply of an information display device is functional, the current technology is to install a manual cut-off switch that disconnects the primary power source from the device. This allows an observer to disconnect the display device from the primary power source and determine whether or not the device remains illuminated by virtue of the backup power supply. Thus, the observer can manually verify whether or not the device will remain lighted in the event the primary power source fails.
FIG. 1 illustrates an example of a circuit diagram for a prior art illuminated information display device with a backup power supply. The circuit shown in FIG. 1 is exemplary of the prior art circuitry for illuminated information display devices. The device 100 is coupled to an external primary power source 105 that illuminates a light source 120. Also coupled to the light source 120 is a secondary power source 130 that is, for example, a battery. Between the external primary power source 105 and the light source 120 is a manual cutoff switch 110. To test the potency of the backup or secondary power supply 130, an observer manually throws manual switch 110 to disconnect the light source 120 from the primary power source 105. Once disconnected from the primary power source 105, the light source 120 is powered by the backup power supply 130. The backup power supply 130 is engaged when a power fail detector 180 senses an absence of power from the primary power source 105. The power fail detector 180 signals a power failure switching device 140 to allow current to flow from the backup power supply 130 through the power failure switching device 140 into the light source 120. The circuit shown in FIG. 1 also includes a recharge circuit 170 that utilizes power from the primary power source 105 to charge the backup power supply 130 when power is supplied by the primary power source. Finally, the circuit of FIG. 1 includes a power transformer 150 to accept an AC voltage and step that voltage up or down, and a rectifier 160 to convert an AC current into a DC current.
As illustrated with the circuit presented in FIG. 1, the prior art illuminated information display devices utilize a manual switch to disconnect the primary power source from the light source. The problem with this technology is that most devices, particularly exit signs, traditionally are located near the ceiling of the area where it is displayed. This location makes maintenance and testing of its battery backup unit extremely difficult. An individual must climb a ladder or similar apparatus to access the illuminated device in order to operate the manual, primary power cut-off switch. This situation not only creates a hazard for the individual on the ladder, but also increases the amount of time required to check the devices and acts to discourage routine checks.
For the foregoing reasons, there is a need for an illuminated information display device that can be easily installed without hard-mounting. Also needed is an information device with a backup power supply, the potency of which may be easily verified remotely.